Arc rupturing device for electric switches



E. LANGE Dec. 8, 1936.

ARC RUPTURING DEVICE FOR ELECTRIC SWITCHES Filed Dec. 10, 1935 Patented Dec. 8, 1936 UNITED STATES ABC BUP'I'URING DEVICE FOR ELECTRIC SWITCHES Y Emil 1m... Berlin-Zehlcndorf, Germany Application December 10, 1935, Serial No. 53,749

In Germany December 10, 1934 3 Claims.

This invention relates-to an electric switch of the kind wherein means are provided for rupturing an arc, formed between the switch contacts, by a blast or jet produced on the heating by the arc itself of a fluid contained in an adjacent chamber.

The object of the invention is to provide means for maintaining the blast itself as cool as possible in order to ensure a reliable rupturing of the are, l and the invention consists essentially in the provision of means for forming one are. at the outlet of a chamber and another are inside a bell in said chamber which communicates with the out-' let through acircuitous route, so that the'pressure produced by the heating of the fluid in said space, will cause the comparatively cold fluid in the principal space of the chamber, to be. ejected through the outlet and to rupture the are at the latter, means being provided for preventing the fluid inside the bell from mixing with the fluid at the outside thereof.

The confined space for the second arc may be formed bya bell supported within the chamber .with the crown turned towards the outlet.

Figs. 1-4 of the accompanying drawing are sectional views of different forms of a switch constructed according to the invention.

Each of the illustrated switches comprises a. chamber [having at one end an outlet 5 which is closed by a spring-controlled valve 6 adapted: to open at a given pressure of the gas or other fluid and closed in the chamber. The switch has a rod-shaped actuating contact 3 which is movably mounted in the end of tlie chamber situated opposite the outlet 5. In the arrangement shown in Figs. 1 and-2 the chamber contains a bell I which is slidably mounted by means of holded lugs 9 on guide rods 8 and controlled by springs II. In the crown of the bell an auxiliary contact 4 is mounted which is formed inside the bell as a socket for the reception of the rod 3. Outside the bell the contact 4 has the form of a pinprovided with a bevelled end which, in the construction according to Fig. l, is adapted to engage a principal, annular contact 2 fitted in the outlet of the chamber. Adjustable collars ID on the rods 8 support the bell inopposition to the springs H and co-operate with the latter. for maintaining the end of the auxiliary contact 4.normally at arc producing distance from the principal contact- 2.

The operation ,is as follows: i

For closing the switch, the rod 3 isadvanced so as to engage the auxiliary contact 4 and press it against the principal contact 2, the bell being advanced together with the contact 4 in opposichamber wall and the projection tion to thesprings l I. On the rod 3 being retracted for breaking the circuit, the auxiliary contact recedes and forms an arc'between it and the principal contact 2. The contact 3 also leaves the contact 4, and a second arc is formed between these contacts inside the bell. Thefluid inside the bell becomes heated by the are and sets up a pressure which is communicated to the space outside the bell and which eventually causes the valve 6 to open. The escaping fluid traverses the arc and forms a blast by which the arc will be ruptured. Since the blast is composed of the comparatively cold fluid contained in the chamber I outside the hell I, a reliable rupture of the arc will. be ensured.

The arrangement shown in Fig. 2 operates in the same manner but diifers from the arrangement of Fig. 1 in that the principal contact has i the form of a. rod I2 which forms a stem for the .valve disc 6 by means of which the outlet is normally closed. The contacts 4 and I2 meet within a ring 2 which ensures a good electric 'connectlon. I

Fig. 3 shows, an arrangement wherein the bell I is rigidly connected to the chamber l by means In order to ensure that the hot fluid from the bell shall not reach the outlet-5; means may be provided for separating the fluid in the bell from that of the outside space. Such an arrangement is shown in Fig. 4. The hell 'I" is in this-case connected at the base to.the chamber land formed at the base with slots through which it communicates with the chamber. the space between the bell and the chamber is an annular piston 5 which separates the fluid Arranged in in the bell from that of the principal chamber space. When the pressure in the bell increases,

the piston will be thrust forwards and will act on the fluid outside the bell for rupturing the are at the outlet as previously described. The chambar I is provided with additional outlet ports l6 which are normally closed by the piston and which are'eventually uncovered thereby as it is moved forwards by the pressure, so that the hot gas can escape through the ports. Between the l4 formed around the outlet, an annular space I8 is formed for the reception of the piston, I 5. The air which is trapped in this space serves as a bufier for the piston and prevents shocks. The piston movemerit may be positively limited by abutments 11 on the bell 7"; r

The are rupture may be efiected either by means of a liquid or a gas, and the-valve which normally closes the outlet 5 may be' omitted.

lclaim: l 1. An electric switch of the character described, comprising a closed chamber containing a-fluid 10 and having an outlet'for the latter, a spring;

pressed closing member for said outlet, a principal contact arranged in said outlet, a bell sup ported within said chamber, an actuating contact, movably mounted in the chamber and located within the bell, a movable auxiliary contact I mounted in the crown of the bell in position to co-operate with the principal contact as well as with the actuating contact, means for preventing.

comprising a closed chamber containing a fluid 30 and having an outlet for the latter, a spring pressed closing member for said outlet, 'a principal contact arranged in said outlet, a bell supported within said chamber, an actuating contact movably mounted in the chamber and located 35 within the. bell, a movable auxiliary contact mounted in the crown of the bell in position to -operate with the principal contact as well as with the actuating contact, an annular piston fluid from outside the bell through the outlet and 10 rupturing the arc in the latter.

3. An electric switch of the character described, comprising a closed chamber containing a fluid and having an outlet for the latter, a spring pressed closing member for said outlet, a prin- 15' cipal contact arranged in said out1et, a bell supported within said chamber, an actuating contact movably mounted in the chamber and located within the bell, a movable auxiliary contact mounted in the crown of the bell in position toco-operate with the principal contact as well as iliary contact at arc forming distance from the principal. contact, the actuating contact being operative to press all the contacts together for closing the circuitand to form an arc inside the bell on the circuit being broken for driving fluid from outside the bell through the outlet and rupturing the arc in the latter.

'- EMIL LANGE. 

